The purpose of this study is to begin to examine the effects of low-level lead acetate exposure on cardiovascular and renal adaptations to pregnancy. The goal of the research is to determine the potential mechanisms responsible for the observation that prior lead exposure causes an increased incidence of pregnancy complications including hypertension in women. Studies will be performed on arteries small enough to determine blood pressure from rats chronically exposed (90 days) to a low-level of lead (25 ppm) in drinking water. Arterial contractile function will be assessed using an pressurized arteriograph. The effect of lead exposure on nitric oxide synthase activity, cGMP production and arterial wall mitochondrial respiration will be measured and compared to control animals. The progression of the toxicity of lead and pregnancy will be monitored using a catheterized rat model. Clearance of inulin and p-aminohippurate will be used to assess renal hemodynamics and glomerular. The proposed study will determine the role of renal toxicity and vascular reactivity in low-level lead exposure. In addition, the study will begin to examine the effects of lead exposures, at levels seen in environmental exposures to humans, have on normal adaptive processes of pregnancy.